A wolf pack is usually a family - a mother and father wolf, their pups from this year, and sometimes older brothers and sisters from last year. A pack might be 4 to 8 wolves. The parents lead - they choose where to hunt, where to rest, when to move on.
Wolves howl to talk to each other. Each wolf has a slightly different voice, so when several wolves howl together it sounds like a strange wild choir. They use howls to find each other when the pack has split up, to tell other packs 'this part of the forest is ours', and sometimes, scientists think, just because it feels good.
Wolves are the wild ancestor of every dog in the world - from huskies and Alsatians right down to chihuahuas. Around 30,000 years ago, some wolves started living near humans, and slowly over time their descendants became the family pets we know today. If you look carefully, even a tiny dog has wolf ears and wolf paws.
Wolves are very important for the forest. They hunt deer, which keeps the deer from eating all the young trees. Where wolves come back to a forest, the trees often grow back stronger. Scientists call this a 'wild forest in balance'.